CAREER: Microstructure of Jammed Particulate Matter

****非技术摘要****该学院早期职业奖支持一个以理解随机堆积粒子的结构和动力学为目标的项目。在给定的密度下，微粒系统会堆积成一种机械稳定且无定形的堵塞状态，其几何形状从视线中隐藏起来。因此，该项目将使用透明的荧光乳剂（一种液体的液滴悬浮在另一种液体中），使用一种称为共聚焦显微镜的特殊显微镜，以3D方式观察液滴的包装。然后，所得到的填料几何形状将测试颗粒随机组织的原理，作为参数的函数，如压力、创建填料的协议、颗粒大小的分布以及颗粒之间的相互作用。本研究旨在通过实验数据的启发，引导对包装的新理论理解。这个问题与基础研究和许多工业有关，从从多孔岩石中提取石油，到在筒仓中储存粮食和将药粉压实成片剂。实验室的研究和纽约地区及其他地区的科学教育的整合将在一个名为Biobus的新移动设备上进行。自2007年启动以来，BioBus已经覆盖了30多所少数民族院校的1万多名学生，得到了学生、教师和媒体的积极响应。****技术摘要****本学院早期职业奖资助一个项目，其目标是在微观尺度上发展对随机包装的理解。共聚焦显微镜将被用来研究堵塞的颗粒物质，使用乳剂系统。然后，对堵塞材料的研究将扩展到它们的动态流变学和微力学性能。通过实验获得单个粒子之间的力及其重排，将评估这些系统中应力松弛和能量耗散的微观机制。用统计模型来理解堆积颗粒材料，不仅会影响工业过程，如石油钻探或粮食储存，还会为复杂系统经历结构停滞的行为提供广泛的见解。除了培训参与软凝聚态物理领域研究的高中生、本科生和研究生外，该教育计划还包括通过一种名为Biobus的新型科学教育设施向K-12学生进行推广。移动实验室为学生提供了一个动态的、动手的科学课程：一个促进对自然世界的探索的课程，这将有助于培养下一代科学家。

****NON-TECHNICAL ABSTRACT****This Faculty Early Career Award supports a project with a goal of understanding the structure and dynamics of randomly packed particles. At a given density, particulate systems pack into a mechanically stable and amorphous jammed state whose geometry is hidden from view. This project will therefore employ transparent, fluorescent emulsions (a suspension of droplets of one liquid in another) to look through the packing of the droplets in 3D using a special type of microscope called a confocal microscope. The resulting geometry of the packing will then test the principles of the random organization of the particles as a function of parameters, such as the pressure, the protocol by which the packing is created, the distribution of sizes of the particles and the interaction between the particles. This study aims to lead the way to a novel theoretical understanding of packing inspired by experimental data. This problem is of relevance to fundamental research and to many industries, ranging from oil extraction through porous rocks, to grain storage in silos and the compaction of pharmaceutical powders into tablets. The integration of the research in the laboratory and the science education in the New York area and beyond will take place on a new mobile facility called the Biobus. Since its start in 2007, the BioBus has reached over 10,000 students at more than 30 different minority-serving institutions and has received an extremely positive response from students, teachers, and the media alike.****TECHNICAL ABSTRACT****This Faculty Early Career Award funds a project with a goal of developing an understanding of random packing on the microscopic scale. A confocal microscope will be employed to study jammed particulate matter, using an emulsion system. The study of jammed materials will then be extended to their dynamic rheological and micromechanical properties. Having experimental access to the forces between individual particles and their rearrangement, the microscopic mechanisms of stress relaxation and energy dissipation in these systems will be assessed. Understanding packed particulate materials with statistical models, would not only impact industrial processes, such as oil drilling or grain storage, but also provide broad insight into the behavior of complex systems experiencing structural arrest. Along with training high-school, undergraduate and graduate students who participate in the research in the area of soft-condensed matter physics, the educational plan involves K-12 outreach through a novel science education facility called the Biobus. The mobile lab provides school students with a dynamic, hands-on science curriculum: one that fosters exploration of the natural world, which will help develop the next generation of scientists.